fix(physics): port retail slope landing stop

docs/ISSUES.md

@@ -142,7 +142,7 @@ remain in place (ride ACDREAM_DUMP_MOTION=1) until the user gate passes.
 
 ## #269 — Slope-stop slide runs too far (post-bounce-rework residual)
 
-**Status:** OPEN (user live gate 2026-07-30 — "almost pass with merits")
+**Status:** DONE — 2026-07-31 (implementation + user live gate)
 **Severity:** LOW-MEDIUM (feel residual; bounce family otherwise accepted)
 **Component:** physics / landing slide decay
 
@@ -162,14 +162,24 @@ cos(10°) with base 0.2); the jump chain end-to-end (`GetJumpHeight`
 Sledding auto-toggle (P2 finding re-confirmed; no `state |= 0x800000`
 writer exists).
 
-**Next step (behavior question, not code):** live A/B per the cdb
-workflow — breakpoints on `calc_friction`/`handle_all_collisions` dumping
-velocity per tick while the retail client lands + slides on a slope, vs an
-`ACDREAM_CAPTURE_RESOLVE` capture of the same maneuver on the same slope.
-Compare the decay curves; the first diverging tick names the mechanism.
-Candidates the trace discriminates: hop-chain cadence (friction skips
-airborne micro-hop ticks), gravity-tangential rebuild timing, quantum
-alignment.
+**Resolution (2026-07-31):** a 2,184-quantum live capture isolated the
+first divergence. The landing tick produced retail's correct 5% reflect,
+but the following quanta repeatedly restored
+`LastKnownContactPlane` while retaining the reflected velocity. The body
+therefore remained Contact + OnWalkable with `v·n > 0.25`, where retail
+`calc_friction` intentionally does no work, and slid at full speed.
+
+Named-retail `CTransition::validate_transition @ 0x0050AA70` revealed the
+omission: its non-OK remembered-plane recovery calls
+`OBJECTINFO::kill_velocity @ 0x0050CFE0` *before* the proximity test and
+plane restore (`0x0050AAED–0x0050AB42`). It also consumes the remembered
+plane only in that non-OK branch and overwrites last-known validity from
+the final contact plane at `0x0050ACFF`. ACDream now follows that exact
+ordering. Focused collision-recovery and clean-advance pins pass; full
+Core (4,107/2 skips) and Runtime (439/0) suites pass; the user repeated the
+slope-jump test and accepted the result (“Perfect! Works great!”).
+Capture and decode:
+`docs/research/2026-07-31-269-slope-stop-capture.md`.
 
 ---
 

docs/plans/2026-04-11-roadmap.md

@@ -46,12 +46,14 @@ a ledger pass. Goal: zero physics TS rows, no unargued feel-affecting AP
 rows, one final batched connected visual matrix. Sonnet implements, Opus
 reviews. The plan is
 [`2026-07-29-physics-parity-campaign.md`](2026-07-29-physics-parity-campaign.md).
-The 2026-07-31 #268 stat-chain package is implemented pending its live visual
-gate: panel and Runtime movement share retail's complete augmentation ordering,
+The 2026-07-31 #268 stat-chain package is implemented and user-accepted:
+panel and Runtime movement share retail's complete augmentation ordering,
 the authored per-fragment vitae/buff/debuff colors are live, and AP-127 plus
-TS-8 are retired by focused and end-to-end packet tests. The remaining
-implementation target is #269's capture-driven slope-slide feel residual,
-followed by the unfinished live matrix rows.
+TS-8 are retired by focused and end-to-end packet tests. #269's
+capture-driven slope-slide residual is also closed and user-accepted:
+`CTransition::validate_transition` now performs retail's non-OK-only
+remembered-plane restore with the preceding `OBJECTINFO::kill_velocity`.
+Campaign P now continues with the unfinished live matrix rows.
 
 ---
 

docs/plans/2026-07-29-physics-parity-campaign.md

@@ -380,13 +380,19 @@ root-caused, retail-ported, and user-accepted in the same session:
   authored 0x1B palette exactly: #7FFFFF vitae, #00FF00 buff, #FF0000
   debuff. TS-8 is also retired: a real live 0x02C2 payload carries its full
   StatMod through dispatch and changes the effective skill immediately.
-- **#269 filed** — slope-stop slide sometimes runs long. `calc_friction`
-  (0x0050ee70) and the complete jump chain (`GetJumpHeight` 0x006b09b0,
-  `InqJumpVelocity` vz=sqrt(h·19.6), 1.0 s/0.8 s powerbar charge) are
-  byte-verified identical — the user's jump-height hypothesis is
-  refuted; next step is the live cdb A/B decay-curve trace.
+- **#269 closed 2026-07-31** — the live 2,184-quantum trace proved the
+  landing reflect and friction math were correct. ACDream omitted retail's
+  `OBJECTINFO::kill_velocity` before restoring a remembered contact plane
+  in `CTransition::validate_transition @ 0x0050AA70`, retaining full
+  downhill velocity while repeatedly re-grounding the mover. The exact
+  non-OK-only restore/kill order and final last-known validity overwrite
+  are now ported, focused/full gates pass, and the user accepted repeated
+  slope jumps. Evidence:
+  `docs/research/2026-07-31-269-slope-stop-capture.md`.
 
 Matrix rows accepted so far: speed parity, roof slide, downhill bounce,
-flat pop, uphill landing (rows 3/4/5-partial/12-partial). Remaining
-rows: 1, 2, 6, 7, 8, 9, 10, 11 plus #269's slide feel. Suite at this
-checkpoint: 10,031 passed / 5 skips / 0 failures.
+flat pop, uphill landing, and #269's slope-stop feel
+(rows 3/4/5-partial/12-partial). Remaining rows: 1, 2, 6, 7, 8, 9, 10,
+and 11. The #269 checkpoint passes 4,107 Core tests / 2 skips and 439
+Runtime tests / 0 skips; the complete Release suite passes 10,061 tests /
+5 skips / 0 failures.

docs/research/2026-07-31-269-slope-stop-capture.md

@@ -0,0 +1,104 @@
+# Issue #269 — slope-stop capture and retail correction
+
+**Date:** 2026-07-31
+**Status:** implemented; user live gate passed
+**Scope:** landing-bounce follow-up, `CTransition::validate_transition`
+
+## Symptom
+
+After the retail 5%-elasticity landing reflection was restored for #265,
+the character could retain too much downhill speed after landing on a
+walkable slope. The user described the residual as “slides too far on
+landing.”
+
+## ACDream live capture
+
+`ACDREAM_CAPTURE_PLAYER_QUANTA=<jsonl-path>` records the local player's
+complete admitted object quantum without changing simulation order:
+
+1. quantum start;
+2. root/PositionManager composition;
+3. pre- and post-`UpdatePhysicsInternal`;
+4. transition result;
+5. final collision-response commit.
+
+The accepted repro contained 2,184 quanta. The clearest landing was:
+
+| Quantum | Event | Velocity |
+|---|---|---|
+| 1740 | final airborne quantum | `(-12.316, 8.187, -26.266)` |
+| 1741 | slope collision, normal `(-0.236, 0.236, 0.943)` | |
+| 1741 post-response | correct 5% reflect | `(-17.391, 13.262, -6.576)` |
+| 1742–1758 | still Contact + OnWalkable, no new collision normal | velocity unchanged |
+| 1759+ | contact relationship changes | friction finally begins decaying |
+
+The reflected velocity had `dot(v, normal) = +1.0252`: it pointed away
+from the slope. Retail `calc_friction` correctly skips while this value is
+at least `0.25`, so friction was not the defect. ACDream was repeatedly
+restoring the remembered slope plane and re-grounding the body without
+performing retail's accompanying velocity stop.
+
+## Retail oracle
+
+Named-retail:
+
+- `CPhysicsObj::check_contact` `0x0050F5B0`
+- `CPhysicsObj::get_object_info` `0x00511CC0`
+- `CTransition::validate_transition` `0x0050AA70`
+- `OBJECTINFO::kill_velocity` `0x0050CFE0`
+
+The exact `validate_transition` order at
+`0x0050AAED–0x0050AB42` is:
+
+1. enter only for a non-OK collision/adjusted/slid result;
+2. if `last_known_contact_plane_valid`, call
+   `OBJECTINFO::kill_velocity`;
+3. test the current sphere center against the remembered plane using
+   `radius + 0.0002`;
+4. restore the contact plane only when still within that distance;
+5. later, at `0x0050ACFF`, overwrite last-known validity with final
+   contact-plane validity.
+
+`OBJECTINFO::kill_velocity` calls
+`CPhysicsObj::set_velocity({0,0,0}, 0)`. ACDream had ported the proximity
+test and plane restore but omitted this call. It also allowed the
+last-known plane to re-ground clean accepted moves, although retail only
+consumes it in the non-OK recovery branch.
+
+## Correction
+
+`Transition.ValidateTransition` now:
+
+- calls `ObjectInfo.StopVelocity()` before the remembered-plane
+  proximity/restore test on a non-OK recovery;
+- performs that restore only in the retail branch;
+- overwrites last-known validity from final contact validity, so a clean
+  move away cannot be re-grounded from stale memory.
+
+The existing `PhysicsEngine.ResolveWithTransition` consumption of
+`VelocityKilled` applies the zero to the canonical `PhysicsBody` before
+the collision-response tail. The initial 5% landing reflection remains;
+only a following collision recovery performs the retail stop.
+
+## Gates
+
+- New focused pins:
+  - collision recovery with a remembered plane kills velocity;
+  - clean advance with a remembered plane neither kills nor re-grounds.
+- Full `AcDream.Core.Tests`: 4,107 passed / 2 skipped.
+- Full `AcDream.Runtime.Tests`: 439 passed.
+- `AcDream.App` Release build: 0 warnings / 0 errors.
+- Complete Release suite: 10,061 passed / 5 skipped / 0 failed.
+- User live gate: **PASS** — repeated slope jumps now settle correctly
+  (“Perfect! Works great!”).
+
+## Diagnostic tools retained
+
+- `tools/analyze_269_slope_stop_capture.py`
+- `tools/cdb/run-issue269-slope-stop.ps1`
+- `tools/cdb/issue269-slope-stop.cdb`
+
+The cdb runner refuses to attach unless the live retail executable matches
+the Sept 2013 named PDB. The locally installed 2015 retail executable does
+not match; the static named-retail decode above is therefore the retail
+oracle used for this correction.